Eating at Night Linked to Depression and Anxiety-Like Moods

Eating during the day might have mental health benefits. 

Using food to alleviate your mood? The time of meals may have an impact on mood, including levels of depression and anxiety, according to recent research. In a study that simulated night work, researchers at Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system, examined the effects of eating during the day and at night as opposed to solely during the day.

Researchers discovered that among individuals in the daytime and nighttime eating groups, anxiety- and depressive-like mood levels rose by 16% and 26%, respectively. This increase was not seen in the group of participants who only ate during the day, indicating that meal timing may affect mood vulnerability. The findings were recently published in the journal Proceedings of the National Academy of Sciences. 

“Our findings provide evidence for the timing of food intake as a novel strategy to potentially minimize mood vulnerability in individuals experiencing circadian misalignment, such as people engaged in shift work, experiencing jet lag, or suffering from circadian rhythm disorders,” said co-corresponding author Frank A. J. L. Scheer, Ph.D., Director of the Medical Chronobiology Program in the Brigham’s Division of Sleep and Circadian Disorders. “Future studies in shift workers and clinical populations are required to firmly establish if changes in meal timing can prevent their increased mood vulnerability. Until then, our study brings a new ‘player’ to the table: the timing of food intake matters for our mood.”

In industrial societies, shift workers make up to 20% of the labor force and are directly responsible for various hospital services, manufacturing jobs, and other essential services. Shift workers commonly encounter a discrepancy between their brain’s internal clock and routine activities like eating and fasting cycles. They also face a 25 to 40% greater risk of developing anxiety and depression.

“Shift workers — as well as individuals experiencing circadian disruption, including jet lag — may benefit from our meal timing intervention,” said co-corresponding author Sarah L. Chellappa, MD, Ph.D., who completed work on this project while at Brigham. Chellappa is now in the Department of Nuclear Medicine, at the University of Cologne, Germany. “Our findings open the door for a novel sleep/circadian behavioral strategy that might also benefit individuals experiencing mental health disorders.

Our study adds to a growing body of evidence finding that strategies that optimize sleep and circadian rhythms may help promote mental health.”

To conduct the study, Scheer, Chellappa, and colleagues enrolled 19 participants (12 men and 7 women) for a randomized controlled study. Participants underwent a Forced Desynchrony protocol in dim light for four 28-hour “days,” such that by the fourth “day” their behavioral cycles were inverted by 12 hours, simulating night work and causing circadian misalignment. Participants were randomly assigned to one of two meal timing groups: the Daytime and Nighttime Meal Control Group, which had meals according to a 28-hour cycle (resulting in eating both during the night and day, which is typical among night workers), and the Daytime-Only Meal Intervention Group, which had meals on a 24-hour cycle (resulting in eating only during the day).

The team assessed depression- and anxiety-like mood levels every hour.

The team found that meal timing significantly affected the participants’ mood levels. During the simulated night shift (day 4), those in the Daytime and Nighttime Meal Control Group had increased depression-like mood levels and anxiety-like mood levels, compared to baseline (day 1). In contrast, there were no changes in mood in the Daytime Meal Intervention Group during the simulated night shift. Participants with a greater degree of circadian misalignment experienced more depression- and anxiety-like moods.

“Meal timing is emerging as an important aspect of nutrition that may influence physical health,” said Chellappa. “But the causal role of the timing of food intake on mental health remains to be tested. Future studies are required to establish if changes in meal timing can help individuals experiencing depressive and anxiety/anxiety-related disorders.”

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